The central enzymes of the aspartate family of amino acid biosynthesis

The aspartate pathway is responsible for the biosynthesis of lysine, threonine, isoleucine, and methionine in most plants and micro-organisms. The absence of this pathway in humans and animals makes the central enzymes potential targets for inhibition, with the aim of developing new herbicides and biocides, and also for enhancement, to improve the nutritional value of crops. Our current state of knowledge of these enzymes is reviewed, including recently determined structural information and newly constructed bifunctional fusion enzymes.